Yes, supermarkets, bars, resturants, take aways, hardware stores - B&Q is good for discounts, car washes - ARC are good. Odd jobbing can be good (as you say: IT for your experi. Also mowing, weeding, painting fences, dog walking, house sitting, baby sitting etc...) but you have to do alot of advertising and push ppl. I find it is better to have a routine job like the businesses in the first sentence. Odd jobs appear to be just that, jobs that appear/dissapear on odd occasions.
I work at Asda 'seasonally' (min 40 hrs per yr but I can work as often as I want). I'm a Chemical Engineer in management in Libya 28 days on 28 days off in my other job.
Cheers
Pete